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Date:   Sat, 25 Jun 2022 10:41:23 -0600
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Subject: Re: [PATCH -next v5 4/8] blk-throttle: fix io hung due to config
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To:     Yu Kuai <yukuai3@huawei.com>,
        =?UTF-8?Q?Michal_Koutn=c3=bd?= <mkoutny@suse.com>, tj@kernel.org
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        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com
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 <75b3cdcc-1aa3-7259-4900-f09a2a081716@huawei.com>
From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <75b3cdcc-1aa3-7259-4900-f09a2a081716@huawei.com>
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On 6/25/22 2:36 AM, Yu Kuai wrote:
> ? 2022/06/24 0:26, Michal Koutn? ??:
>> On Thu, Jun 23, 2022 at 08:27:11PM +0800, Yu Kuai <yukuai3@huawei.com> wrote:
>>>> Here we may allow to dispatch a bio above current slice's
>>>> calculate_bytes_allowed() if bytes_skipped is already >0.
>>>
>>> Hi, I don't expect that to happen. For example, if a bio is still
>>> throttled, then old slice is keeped with proper 'bytes_skipped',
>>> then new wait time is caculated based on (bio_size - bytes_skipped).
>>>
>>> After the bio is dispatched(I assum that other bios can't preempt),
>>
>> With this assumptions it adds up as you write. I believe we're in
>> agreement.
>>
>> It's the same assumption I made below (FIFO everywhere, i.e. no
>> reordering). So the discussed difference shouldn't really be negative
>> (and if the assumption didn't hold, so the modular arithmetic yields
>> corerct bytes_skipped value).
> Yes, nice that we're in aggreement.
> 
> I'll wait to see if Tejun has any suggestions.

I flushed more emails from spam again. Please stop using the buggy
huawei address until this gets resolved, your patches are getting lost
left and right and I don't have time to go hunting for emails.

-- 
Jens Axboe